1 files changed, 71 insertions, 0 deletions
diff --git a/gfx/2d/AutoHelpersWin.h b/gfx/2d/AutoHelpersWin.h
new file mode 100644
index 0000000000..733f8a1e27
--- /dev/null
+++ b/gfx/2d/AutoHelpersWin.h
@@ -0,0 +1,71 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_gfx_AutoHelpersWin_h
+#define mozilla_gfx_AutoHelpersWin_h
+
+#include <windows.h>
+
+namespace mozilla {
+namespace gfx {
+
+// Get the global device context, and auto-release it on destruction.
+class AutoDC {
+ public:
+  AutoDC() { mDC = ::GetDC(nullptr); }
+
+  ~AutoDC() { ::ReleaseDC(nullptr, mDC); }
+
+  HDC GetDC() { return mDC; }
+
+ private:
+  HDC mDC;
+};
+
+// Select a font into the given DC, and auto-restore.
+class AutoSelectFont {
+ public:
+  AutoSelectFont(HDC aDC, LOGFONTW* aLogFont) : mOwnsFont(false) {
+    mFont = ::CreateFontIndirectW(aLogFont);
+    if (mFont) {
+      mOwnsFont = true;
+      mDC = aDC;
+      mOldFont = (HFONT)::SelectObject(aDC, mFont);
+    } else {
+      mOldFont = nullptr;
+    }
+  }
+
+  AutoSelectFont(HDC aDC, HFONT aFont) : mOwnsFont(false) {
+    mDC = aDC;
+    mFont = aFont;
+    mOldFont = (HFONT)::SelectObject(aDC, aFont);
+  }
+
+  ~AutoSelectFont() {
+    if (mOldFont) {
+      ::SelectObject(mDC, mOldFont);
+      if (mOwnsFont) {
+        ::DeleteObject(mFont);
+      }
+    }
+  }
+
+  bool IsValid() const { return mFont != nullptr; }
+
+  HFONT GetFont() const { return mFont; }
+
+ private:
+  HDC mDC;
+  HFONT mFont;
+  HFONT mOldFont;
+  bool mOwnsFont;
+};
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif  // mozilla_gfx_AutoHelpersWin_h